1. Field of the Invention
This invention relates generally to a process and apparatus for detecting and sorting out inappropriately filled packages of filler material during a packaging process, each package comprising a bottom foil having spaced nests formed therein and a cover foil, and at least the bottom foil being permeable to radiation so that when irradiated on one side thereof with a source of radiation the intensity of the radiation allowed to pass through the bottom foil is measured by at least one radiation receiver. The bottom foil may be otherwise of a material capable of reflecting incident radiation so that when irradiated with a source of rays the reflected radiation is measured by the radiation receiver.
It is to be understood that a radiation permeable foil is one through which rays may pass. The foil may thus comprise a light permeable foil material, whenever the source of rays is a source of light. The receiver may correspondingly comprise a photo element. And, the source of radiation may comprise an infrared radiator so that a non-transparent foil material will be selected. Whenever the bottom foil only is permeable to rays, the detection of inappropriately filled packages is carried out prior to the sealing of the package nests with the cover foil. However, if both bottom and cover foils are permeable to radiation, then such detection may be carried out after the cover foil is sealed in place.
And, it is to be understood that when the foil is described as capable of reflecting incident radiation, it may be of a material capable of reflecting visible light whenever the source of radiation comprises a light source. A photo element would thus be selected as the receiver. The transmitter or source of radiation may alternatively comprise an infrared radiator.
2. Description of the Prior Art
In the production of deep-dished packages for filler material, the bottom foil is normally drawn off a supply roll and is fed through deflecting rolls during the packaging process for forming a plurality of nests. The bottom foil having the nests formed therein are then guided through the filling station and are filled with the selected filling material which may comprise pills, tablets, or the like, after which the cover foil is welded or otherwise secured in place. The nests of the package are generally disposed in rows both parallel to and perpendicular to the direction of movement of the packages through the packaging machine. The cover foil overlies several mutually perpendicular rows of spaced nests, and the covered packages are fed to a stamping station at which they are stamped and cut into packages of predetermined numbers of spaced nests. And, those subdivided packages having one or more nests thereof inappropriately filled with the filler material are sorted out in some manner by rejecting them as not meeting the necessary quality control standards.
In order to detect inappropriately filled packages, it has been known to provide mechanical arrangements disposed between the filling station and the sealing station above the bottom foil. By such arrangements, pegs, levers, or roller levers are lowered into the nests and a signal is obtained upon direct contact with the filler material or with the nest to determine whether the nest is appropriately filled. And, the pegs or levers are normally combined into groups capable of use with only a predetermined array of nests for a particular package.
Moreover, German Pat. No. 26 31 138 discloses an apparatus for detecting and sorting out faulty packages which are made during a packaging process. A video picture is taken of a package free of faults and is stored electronically, and succeeding video pictures of the package nests filled with the particular filler material are then compared against this stored video picture. A video camera located behind the filling station photographs ranges of the bottom foil always representing a group of packages predetermined according to length and width. Thus, an arrangement is developed such that filled nests of a package group in the photographed area imbued with faults or without faults determined by comparison are recognized, and the inappropriately filled packages of a pertinent group of packages are sorted out after a stamping operation.
It has also been known to carry out a detecting and sorting out process by a transmitted light technique, whereby a light transmitter is disposed on one side of the bottom foil with a light receiver on the other side. Interruption of the ray of light is therefore indicative of whether or not the nests are filled, the filler material providing an opto-electronic barrier.
Further, in the present area to which the present invention relates, it is known to dispose a transmitter and a receiver in such a matter that the reflected light is picked up by the receiver. Thus, whenever a nest of the package is empty the intensity of the light is insufficient to actuate response by the receiver. Only when the path of the light rays is shortened by a filler material located in the nest will the receiver respond, since the filler material acts as an opto-electronic barrier. However, it is not possible with these known techniques to determine whether or not the filler material has the prescribed size but only whether the particular are filled or not. It has therefore not been possible to sort out packages containing faulty filler material contained within one of the package nests.